Industrial robot

ABSTRACT

The present invention is an industrial robot which has a feed screw that can be easily position in relation to the direct-acting guide. It has a power transmission device that can be removed from the supporting frame which the feed screw is left attached to the supporting frame, so that positioning of the feed screw is very easy. 
     As a result if the simplicity in design machining is only required for the attaching surface for the direct-acting guide, the middle plate, the top plate, and the bottom plate, the cost of production is reduced.

TECHNICAL FIELD

The present invention relates to an industrial robot having adirect-acting mechanism.

BACKGROUND ART

A horizontal multi-joint type pelletizing robot shall be described withreference to the drawings. FIG. 2 is a sectional side view showing aprior-art horizontal multi-joint type pelletizing robot, whichrepresents a mechanism of a horizontal or vertical acting shaft of aprior-art industrial robot having a direct-acting mechanism in thehorizontal and vertical direction.

The supporting frame 1 has a rectangular parallelepiped box-shapedstructure, in which the front face is opened, and which comprises topplate 11, back plate 12, bottom plate 13, two unillustrated side plates,and middle plate 14 whose three sides are fixed to the top plate 11 andboth side plates are disposed inside. The upper surface of the top plate11, the lower surface of the bottom plate 13, and the front surface ofthe middle plate 14 are machined so as to be parallel or vertical toeach other. At the bottom plate 13, fitting hole 15 is machined by beingcentered on the basis of the machined surface of the middle plate 14.

A direct-acting guide, 2 is fixed at the machined surface of the frontsurface of the middle plate 14. A power transmission device 4 such as agear box, which has a convex part 41 precisely processed at the lowersurface. The power transmission device 4 is positioned within ahorizontal plane by fitting the convex part 41 into the fitting hole 15,and furthermore, positioned so as to be at a predetermined position andhave a predetermined posture with respect to the direct-acting guide 2by adjusting an unillustrated positioning tool, and fixed at the bottomplate 13. A motor, 5 is fixed to the power transmission mechanism 4, andan unillustrated drive shaft of the motor 5 is coupled with the powertransmission device 4. A feed screw 6 comprised of a screw body 61, anut part 62, an upper bearing 63, and a lower bearing 64.

At the lower end part of the screw body 61, an unillustrated spline isformed, which is engaged with an unillustrated gear of the powertransmission device 4. The lower bearing 64 is fixed to the powertransmission device 4, and the upper bearing 63 is fixed to the machinedsurface of the upper surface of the top plate 11. The feed screw 6 isparallel to the direct-acting guide 2, and is adjusted and positioned ata predetermined space. An arm supporting slider 7 is slidably supportedby the direct-acting guide 2, and fixed to the nut part 62. The armsupporting slider 7 is driven by the motor 5 via the power transmissiondevice 4 and feed screw 6 to vertically move along the direct-actingguide 2.

An arm part 8 is comprised of a first arm 81, second arm 82, and a wrist83. The first arm 81, second arm 82, and wrist 83 are rotatably attachedaround respective unillustrated vertical shafts of the arm supportingslider 7, the first arm 81, and the second arm 82, respectively, anddriven by an unillustrated motor. At the front end of the wrist 83, anunillustrated hand, etc. is attached, whereby the hand holds articles.

Thus, this horizontal multi-joint type pelletizing robot works to carryarticles held by the hand to an optional location and load themfollowing commands by an unillustrated controller.

However, in FIG. 2 when the feed screw 6 is attached to the supportingframe 1, it is difficult to correctly adjust and position the feed screw6. The feed screw 6 must be positioned on the basis of both thedirect-acting guide 2 and power transmission device 4. This problem isdescribed as follows.

For positioning of the feed screw 6, the following procedures arerequired: (1) the power transmission device 4 is fixed to the bottomplate 13; (2) the lower end part of the screw body 61 is inserted intothe power transmission device 4, and the lower bearing 64 is fixed tothe power transmission device 4; (3) the upper bearing 63 is temporarilyfixed to the power transmission device 4; and (4) on the basis of theattaching position of the lower bearing 64, while measuring the distanceand inclination of the feed screw 6 from the direct-acting guide 2, thefixing positions of the nut part 62 and upper bearing 63 are finelyadjusted so that a predetermine parallel condition is obtained.

Thus, the simultaneous fine adjustments of the two fixing positions ofthe nut part 62 and upper bearing 63 on the basis of the attachingposition of the lower bearing 64 are troublesome operations and taketime.

Also, unless the feed screw 6 is removed, since the power transmissiondevice 4 cannot be removed from the supporting frame 1, in order toreplace and fix the power transmission device 4, the feed screw 6 mustbe removed, and positioning of the feed screw 6 must be performed ateach time of replacement.

Furthermore, since the supporting frame 1 needs precise machining forthe three surfaces of the top plate 11, bottom plate 13, and middleplate 14, machining man-hours increase, and the cost also increases.

SUMMARY OF THE INVENTION

The object of the invention is, therefore, to provide an industrialrobot in which the feed screw can be easily positioned in relation tothe direct-acting guide, while having a power transmission device thatcan be removed from the supporting frame while the feed screw is leftattached to the supporting frame.

In order to solve the above problems, a feed screw supporting member isattached to a supporting frame. The feed screw is positioned and fixedto the feed screw supporting member at a predetermined relative positionfrom the direct-acting guide, and a power transmission device ispositioned based on the feed screw, and fixed to the screw supportingmember. Also, a space is provided between the supporting frame and powertransmission device by which, while the feed screw is left attached tothe feed screw supporting member, the power transmission device isremoved from the feed screw supporting member, and the front end of thefeed screw is pulled and removed from the power transmission deviceprovided, whereby the power transmission device can be pulled out fromthe supporting frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the embodiment of the invention.

FIG. 2 is Prior Art.

DETAILED DESCRIPTION OF THE DRAWINGS

Hereinafter, the embodiment of the invention shall be described withreference to the drawings.

FIG. 1 is a sectional side view of a horizontal multi-joint typepelletizing robot showing a feed screw supporting member 3 fixed tomiddle plate 14. The feed screw 6 fixes upper bearing 63 to the middleplate 14 via bracket 65, and the lower surface of the lower bearing 64is received by the upper surface of the feed screw supporting member 3,whereby the lower bearing 64 is fixed and attached to the feed screwsupporting member 3.

The lower end part of screw body 61 of the feed screw 6 is inserted intopower transmission device 4, and engaged with an unillustrated gear ofthe power transmission device 4 by an unillustrated spline. The powertransmission device 4 is positioned on the basis of the feed screw 6,and fixed to the feed screw supporting member 3. A predetermined spaceis provided between the power transmission device 4 and the bottom plate13, whereby the power transmission device 6 can be separated and removedfrom the feed screw 6 by being moved down to the bottom plate 13 whilethe feed screw 6 is left fixed to the feed screw supporting member 3.

Also, in the supporting frame 1, the attaching surface for thedirect-acting guide 2 of the middle plate 14 must be machined so as tohave a predetermined flatness, however, since no part is attached to thetop plate 11 and bottom plate 13, they do not need to be machined.

The positioning adjustments of the feed screw 6 can be simplified asfollows: (1) the feed screw 6 is inserted into the feed screw supportingmember 3 and stood up, and the lower surface of the lower bearing 64 andthe upper surface 31 of the feed screw supporting member 3 are puttogether; (2) the distance between the feed screw 6 and direct-actingguide 2 is measured, the upper bearing 63, nut part 62, and lowerbearing 64 are finely adjusted so that the feed screw 6 is at apredetermined position from the direct-acting guide 2; (3) the lowerbearing 64 is fixed to the feed screw supporting member 3; (4) the upperbearing 63 is fixed to the middle plate 14; (5) the nut part 62 is fixedto arm supporting slider 7; (6) the power transmission device 4 isinserted from the feed screw supporting member 3, lifted up, and fittedwith the feed screw 6; and (7) on the basis of the feed screw 6, thepower transmission device 4 is positioned and fixed to the feed screwsupporting member 3.

Thus, since the feed screw 6 can be positioned on the basis of thedirect-acting guide 2 regardless of the power transmission device 4,positioning of the feed screw 6 is very easy.

Also, the power transmission device 4 is attached by only being fittedwith the geed screw 6 whose positioning has been completed.

Also, since the power transmission device 4 can be separated from thefeed screw 6 by being disconnected from the feed screw supporting member3 and moved down to the bottom plate 13, it can be removed while thefeed screw 6 is left fixed to the screw supporting member 3.

Furthermore, the machining in the manufacturing of the supporting frame1 is applied only to the attaching surface for the direct-acting guide 2of the middle plate 14, and the top plate 11 and bottom plate 13 do notrequire machining, therefore, machining man-hours and cost can bereduced.

In this embodiment, the direct-acting mechanism in the verticaldirection is as described can also be applied to the direct-actingmechanism in the horizontal direction.

As described above, in the invention, an effect can be obtained, thatregardless of the power transmission device the positioning adjustmentsof the feed screw becomes easier since the feed screw can be positionedon the basis of the direct-acting guide. Also, the power transmissiondevice can be removed from the supporting frame while the feed screw isleft fixed to the supporting frame because a space is provided betweenthe power transmission device and the bottom plate of the supportingframe.

What is claimed is:
 1. An industrial robot which comprises: a supportingframe; a direct-acting guide fixed to the supporting frame; a feedscrew, having a nut part, attached to the supporting frame parallel withthe direct-acting guide; an arm supporting slider fixed to the nut partof the feed screw and slidably supported by the direct-acting guide; apower transmission device; a motor, fixed to the power transmissiondevice, for driving the feed screw to transmit power between the motorand feed screw; and a feed screw supporting member attached to thesupporting frame, the feed screw being positioned at a predeterminedrelative position from the direct-acting guide and fixed to the feedscrew supporting member, with the power transmission device beingpositioned along a shaft center of the feed screw, and fixed to thesurface of the feed screw supporting member opposite the surface withthe feed screw attached.
 2. An industrial robot as set forth in claim 1,wherein a space is provided between the supporting frame and powertransmission device so that, while the feed screw is left attached tothe feed screw supporting member, the power transmission device can beremoved from the feed screw supporting member and pulled out from thesupporting frame.